1. Field of the Invention
The present invention relates to a digital demodulating technique for receiving and demodulating a modulated signal transmitted from a digital transmitting apparatus.
2. Description of Related Art
In recent years, as a digital demodulating apparatus that receives and demodulates a modulated signal transmitted from a digital transmitting apparatus, a digital demodulating apparatus is proposed that can realize a decrease in power consumption. For example, JP-A-2001-251275 discloses a digital demodulating apparatus that can realize a decrease in power consumption by turning the power of each circuit element constituting a tuner and a demodulator on/off for a proper time.
When the power of a circuit element constituting a tuner or a demodulator is controlled, it may cause generation of noise in a received signal to worsen the status of the signal though it is dependent on factors such as a control timing and a control time period. In such a case, for example, in the case that a portion of the received signal has been completely broken and thus data can not be taken out from the portion, it is useless that the demodulator performs the same demodulation processing as in the case of the normal status of the signal, to the portion where the signal status has been worsened. This brings about extra power consumption for the useless processing.